Taxpayers are pretty much always going to be worse off helping the homeless. Only a small fraction of the chronically homeless will become tax positive citizens in their lifetime.

Either you start off with the first principle that it's OK for wealth-transfer schemes to make tax payers 'worse off' via compelled charity, or I don't think you can get to the point of supporting generalized homeless relief programs. Maybe programs targeted at short-duration stuff to get people into jobs that are capable of doing them and a housing contract might work, but it'd have to be extremely well thought out and wouldn't benefit most chronic homeless.